This invention relates to methods and apparatus for mechanical removal of plaque and thrombolytic material from the interior of veins and arteries in the human body.
Apparatus for mechanical removal of plaque and thrombolitic material from the interior veins and arteries in the human body is disclosed in U.S. Pat. No. 4,990,134.
In one of its aspects, this invention provides an atherectomy device for removing plaque from the interior of the lumen upon travel of the device therethrough where the device includes a rotatable head having nose, central and tail portions. The nose portion is preferably bulbously curved outwardly and defines a forward extremity of the head for initial passage within the lumen. The nose portion is preferably of circular shape at juncture with a central portion with the center of the circular shape being coincident with a longitudinal passageway extending through the head.
The tail portion is preferably separated from the nose portion by the central portion and defines a rear extremity of the head as the head portion passes through the lumen. The tail portion is preferably of rectangular transverse cross-section and tapers from a relatively smaller maximum diameter at juncture with the central portion to a relatively larger maximum diameter at a rear extremity of the rotatable head.
The central portion preferably transitionally tapers from and connects the circular central portion to the rectangular transverse cross-section tail portion with the central portion preferably being of larger transverse cross-sectional area at juncture with a tail portion than at juncture with the nose portion.
The head preferably has a plurality of longitudinally extending cutting grooves formed therein commencing proximate juncture of the circular nose portion and the central portion, with the cutting grooves extending rearwardly therefrom.
The head preferably further includes a central passageway extending the longitudinal length thereof coincidentally with the longitudinal axis of the head and adapted for passage therethrough of wire means for guiding travel of the head through the lumen.
At least some of the cutting grooves in the surface of the head preferably extend along the central portion and the rear portion.
The passageway through the head preferably includes an enlarged portion at the rear end of the head for securement to the head of means for rotating the head.
The cutting grooves preferably extend along the surface of the non-tapering sides of the rectangular cross-section of the tail portion.
The cutting grooves preferably transition longitudinally from V-shapes to rectangular shapes.